Unless otherwise indicated herein, the description in this section is not prior art to the claims in this application and is not admitted to be prior art by inclusion in this section.
In an output process of color image data, it may be difficult to identify difference of colors of an object such as a table and a graph presumed to be identified by difference of colors (color coding) depending on an output destination.
This occurs, for example, when a color image displayed on a monitor of a personal computer or a similar device is printed in a single color or when the color image is projected on a screen with a projector apparatus.
When the color image is printed in a single color, for example, monochrome, the difference of colors cannot be identified depending on expressive power and performance of an image forming apparatus. When the color image is sent to the projector apparatus to project the color image on the screen, a tint on the screen differs from a tint on the monitor, thus failing to identify the difference of colors. Both cases may have a problem of incorrect transmission of information.
As a technique for preventing such incorrect transmission of information, style information according to color information is added to characters in data and the image data is converted when performing monochrome print from color image data. This technique ensures recognizing character colors with styles adding hatching, an underline, or an enclosure line, thus ensuring preventing incorrect transmission of information.
However, the technique cannot be applied to figures such as tables and graphs with no style information.
On the other hand, the following techniques are also available. For a pie chart of color image with a plurality of colored regions, print densities are differentiated among the colored regions. Additionally, there is a technique that detects a color boundary portion at which colored regions of different colors are in contact with one another on a color image and distinguishes the color boundary portion, for example, on a monochrome image.
However, the all above-described techniques do not consider performance of the output destination of the color image. Accordingly, solving the difficulty in seeing a boundary between the colored regions of the color image that varies depending on the output destination is still insufficient.